Electronic readers are becoming increasingly popular. Many such devices incorporate electrophoretic displays or other types of display screens that are not backlit. These display screens therefore require an additional lighting source to allow the display screen to be read at night or under other low ambient light conditions.
One approach to addressing this issue is to incorporate a retractable reading lamp into the reader housing. The reading lamp is deployed as needed in order to provide the requisite illumination of the display screen. A similar approach is to use a detachable reading lamp that clips onto the housing.
Unfortunately, these approaches are problematic in that the reading lamp is cumbersome and can be easily bumped into and misaligned. Also, because of the angled illumination provided by such arrangements, glare is often introduced, making reading difficult. Moreover, the power consumption associated with such arrangements is often excessive, and can therefore quickly drain reader batteries. Similar problems arise with existing wedge-type illumination devices that are used in conjunction with electronic readers.
Alternative approaches incorporate side light sources directly into the reader housing. A problem with arrangements of this type is that user control of the light sources in unduly limited, resulting in inefficient lighting arrangements that can exhibit excessive power consumption. For example, in such arrangements a user generally cannot easily manipulate the light sources to illuminate desired portions of the display screen in a selected regular pattern that conforms to the reading speed and style of the user.
Accordingly, a need exists for improved illumination devices that overcome the drawbacks of the conventional approached described above.